Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the response contents (plan features, credit costs, currency, URLs). It says nothing about size, caching, or freshness of pricing data, which keeps it from a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the caller intent, then the payload contents. The long parenthetical feature list is dense but each item tells the agent what it can answer. Slight redundancy between 'how publishing works' in the trigger and the second sentence's restatement.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the description needn't explain return values, and annotations cover the safety profile. One optional parameter with full schema documentation means little else is needed. The enumerated content areas are enough for an agent to decide relevance and call correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the single enum parameter has its own description with example values and a default, so the schema carries the burden. The tool description never mentions the locale parameter or that it governs the language of returned names and URLs, so it adds nothing beyond the schema. Baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names the resource and enumerates its contents precisely: free account scope, paid plans with EUR prices, credit costs, and sign-up/pricing/guide URLs. An agent knows exactly what it gets back. It does not explicitly contrast itself with siblings like get_catalog, but the informational nature makes the distinction obvious in practice.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives a concrete trigger: 'when an owner, broker, agency or developer wants to advertise a property for sale or rent, or asks how publishing on new.estate works or what it costs.' This is strong intent-based guidance. It stops short of stating when NOT to use it or naming an alternative for adjacent pricing/account questions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.